Field of the Invention
The present invention is directed to freezable oil-in-water emulsions comprising an oil comprising one or more polyunsaturated fatty acids, and processes for preparing the freezable oil-in-water emulsions.
Background
Polyunsaturated fatty acids (“PUFAs,” including long-chain PUFAs “LC-PUFAs”) have been shown to enhance cognitive function and maintain cardiovascular health, among other benefits. In particular, omega-3 PUFAs are important dietary components for preventing arteriosclerosis and coronary heart disease, for alleviating inflammatory conditions, and for retarding the growth of tumor cells, and omega-6 PUFAs are important as both structural lipids, and as precursors for, e.g., prostaglandins and leukotrienes. PUFAs are an important element of a healthy diet, but because PUFAs are not synthesized by humans in vivo, these compounds must be ingested. For example, the oils of many plants and animals (e.g., fish, walnuts, lingonberries, hemp, algae and the seeds and/or leaves of several plants such as flax, chia, perilla and purslane) are rich in PUFAs. Many people also choose to ingest PUFAs through dietary supplements and/or PUFA-enhanced food products. As a result, consumer demand for products that containing PUFAs has recently increased, and a wide range of products now contain PUFAs.
Oil-in-water emulsions have been used as a vehicle for PUFAs, both as a precursor for preparing comestibles, and in particular, as a component in formulated beverages, foods, nutraceuticals, and pharmaceuticals. However, PUFAs present in an emulsion can become unstable and degrade (e.g., via oxidation and/or photolytic degradation), and therefore, maintaining the physical and chemical stability of PUFAs in an emulsion is critical. Freezing a PUFA-containing oil-in-water emulsion is an attractive means for reducing the oxidative potential of PUFAs during shipment and/or storage. Unfortunately, freezing can lead to de-emulsification, and require extended periods of time for thawing prior to use.
What is needed is an oil-in-water emulsion that remains flowable and is resistant to de-emulsification and changes in particle size at sub-freezing temperatures (i.e., temperatures less than 0° C.). Furthermore, what is needed is a freezable oil-in-water emulsion that is resistant to oxidative degradation of a PUFA contained therein.